The 12:25 p.m. crash occurred when the driver of the tractor-trailer carrying cotton trash failed to yield and hit the train, authorities said. The impact pushed the two passenger cars and the locomotive off the tracks south of Hanford, a farming town.

The train traveled about 600 feet after the collision before hitting a switchback and derailing, according to California Highway Patrol Officer Scott Harris.

Officials have not determined how fast the train or the truck were going, but the average speed for Amtrak through the area is 70 to 80 mph, while the speed limit on the roadway where the truck was traveling is 55 mph, Harris said.

After the crash, metal pieces from the truck could be seen inside the train, which was covered by cotton seeds. Several pieces of luggage were also scattered around the area.

Kings County Assistant Sheriff Dave Putnam described the injuries to passengers as bumps, bruises, scrapes and possibly broken bones.

The crash occurred at a crossing that was equipped with gates to stop traffic, Putnam said.

Eight of the injured passengers were taken to Adventist Medical Center in Hanford and five more were expected, said hospital spokeswoman Christine Pickering. She did not provide details on the extent of their injuries.

“We did call in additional physicians and staff,” Pickering said.

Four additional injured passengers were taken to nearby Adventist Medical Center in Selma, while seven people were taken to Community Regional Medical Center in Fresno, officials said.

The train was on its way from Oakland to Bakersfield, according to Amtrak. It had four rail cars and a locomotive.

The truck driver suffered minor injuries, according to California Highway Patrol spokesman Jerry Pierce. Investigators will try to determine if the crash was caused by driver error, a malfunctioning crossing arm, or something else, the CHP said.

Pierce said the other passengers have been taken to an auditorium in Hanford, where they will board a train and continue to their destinations or family members will pick them up.

All train service through the area has been stopped, with the work of moving the derailed rail cars and repairing the tracks expected to last through Tuesday morning, officials said.

Initially, Amtrak had expected to resume service through the area in time for the morning rush hour, but Amtrak spokesman Cliff Cole said late Monday that a bus bridge would carry passengers between Bakersfield and Hanford until at least 7:15 a.m.

“We will wait for further word from BNSF to see if we need to make further adjustments,” Cole said.

BNSF Railway Co., which operates the tracks, expected to have the tracks open by 7 a.m., spokeswoman Lena Kent said.

Meanwhile, authorities were at the scene of a second accident involving a freight train and a tractor-trailer about 10 miles away.

In the second collision, which took place around 4 p.m., the truck driver suffered major injuries, according to the CHP. No additional details have been released.